SideWinder has just now released an update to UnrealPolyEd, bumping up the version number to 0.7. Importing .t3d files from UnrealEd is now an option, but with certain limits, as described in the forum thread.

Thanks for your continued support of the mapping community, SideWinder.

I am the Unreal archivist and historian. If you have something from the past of Unreal that I don't have, do tell.